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Re: #QMX #Finals...did I kill it?
#qmx
Good luck Bill! Let us know how it goes, please. I've been putting out 3.5w on 20m and 5.5w everywhere else for 5 months or so of regular operation, so seeing 0.2w really bummed me out ?.?
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Re: #QMX #Finals...did I kill it?
#qmx
I think we have different root issues, Giuseppe...I do still have RF coming out, it's just a tiny fraction of what it was.
If you're running a windows OS, go to Start button, Run Program, and type 'putty', then hit run. It should have Putty already on your computer.? Then when it pulls up the window to determine which port you want to access, select 'Serial' then type COM* where * is the number for the comport your QMX registers when plugged into your computer.? I'm not very good at explaining things, and I'm not a computer geek, sorry if this doesn't help. |
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Re: #QMX #Finals...did I kill it?
#qmx
My QMX is reading <.5w on all channels in the Putty diagnostic.? I have a QRP power meter that outputs to my DVM and that showed the QMX at almost 4w on 20m!? Below is the schematic for the QRP power meter.? My cheapo SWR/Power meter shows about the same.? It's a rainy day here in Mobile, AL and I'm gonna reflow all the toroids and transformers.
-- Bill Harbour K4VIB |
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Re: #QMX #Finals...did I kill it?
#qmx
GIUSEPPE
good morning everyone, a similar problem happened to me with the high band qmx, after 10 hours of transmission and in wspr 10 mt, it went from 5W to 0w, the RF no longer comes out, I replaced the bs170 mosfets and nothing has changed , how can I access PUTTY to control the qmx, I don't know how to do it.? Thanks 73 Giuseppe iu8eun Il Ven 1 Mar 2024, 13:00 mordan42 via <mordan42=[email protected]> ha scritto: On Fri, Mar 1, 2024 at 05:49 AM, John Z wrote: |
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Re: #QMX #Finals...did I kill it?
#qmx
On Fri, Mar 1, 2024 at 05:49 AM, John Z wrote:
?Yes, I can. I'll do that Sunday or Monday morning and post the results here (at work today, usher in a wedding tomorrow morning). The diagnostics on Putty were showing 0.2 watts, and the Kenwood AT-230 was showing about a quarter watt. I know signal was getting out because this was first observed during a JS8 heartbeat signal which received acknowledgements from the Southeast and Midwest states, even with the tiny power... |
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Re: #QMX #Finals...did I kill it?
#qmx
OK. How are you measuring output power? Can you measure current drawn from the power supply while transmitting? On Fri, Mar 1, 2024, 5:18?AM mordan42 via <mordan42=[email protected]> wrote: Receive looks okay. Waterfall was showing incoming FT8 signals. I'll check anyway, thanks! |
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Re: #QMX #Finals...did I kill it?
#qmx
Receive looks okay. Waterfall was showing incoming FT8 signals. I'll check anyway, thanks!
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Re: #qdxm QDX-M - new single-band version of QDX available
#qdxm
Hi,
I made my mono a dual band QMX-M: 12m and 10m. I have set my QMX-M for High bands instead for Mono band so I got settings for all 5 bands from 20m to 10m in the setup menu.? I suppose you could do the same also for the low band version and than adjust the parameters to your needs. -- 73 Bojan S53DZ |
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Re: #QMX #Finals...did I kill it?
#qmx
Mordan42,
Hans sells BS170s in his component area: Those would be the same as the ones supplied with the kit.?? 73 Evan AC9TU |
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High insertion loss / early rolloff 6m LPF
I've assembled and tested the LPF kit from 160m to 6m. All the filters work as expected without adjustment except 6m. The 6m filter starts to roll off very early and has a high loss in the 6m band (over 4db at 52Hz).? I've checked for solder bridges and cold joints, continuity is good through the inductors and all the pads that should be connected. I can't find any shorts anywhere. Any thoughts? - Justin, AI6YM |
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Re: #qdxm QDX-M - new single-band version of QDX available
#qdxm
Hello Nate? The QDX-M firmware displays only a single entry in the Band Configuration screen. The single entry is configured automatically by the firmware for the band you choose to build the kit for, controlled by your choice of jumper wires (install following the instructions in the assembly manual).? The firmware doesn't have defaults set up yet for all those other bands. So you would need to set up the band you want, manually, in the terminal.? 73 Hans G0UPL |
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Re: QMX Band Pass Filter (and Band pass filters in general) question
Hans ,? Jonathan says? -? "I am not even sure if a single resonant band pass filter is the best option for my use.." |
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Re: #QMX #Finals...did I kill it?
#qmx
Mordan42, How is it doing on receive? Check C510 and C526 to see if they are damaged. If either have cracked or have been overstressed by high RF current, output power will be very low. JZ KJ4A? On Thu, Feb 29, 2024, 10:24?PM Ham Radio <bernard.murphy@...> wrote: Digikey has BS17s in stock ?for 0.59 each.? Buy 10 and you will have spares … |
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Re: Low Band QMX Spectrum analyzer measurments
On Thu, Feb 29, 2024 at 06:52 PM, Chris wrote:
I reckoned that if the manufacturer wrote the maximum limit on the front of the analyser that was what it would cope with."Cope with" and "make accurate measurements with" are different things.?? 73, Don N2VGU |
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Re: Magical smoke out of QDX, two leftmost BS170 very hot
Congrats on successful surgery! I second the suggestion to add an L14 diode to protect against a possible failure mode that sounds consistent with what you described. Other than the L14 voltage, I have also observed low efficiency and resulting thermal dissipation issues for my hi-band QDX only on 10m; 20-12m are fine. So you could also check whether the efficiency looks okay across all bands for you.
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#QMX #Finals...did I kill it?
#qmx
Hello all! I have a QMX rev. 1 low band that has faithfully served me on 19 POTA activations, almost 1,000 QSOs and, recently, I was successfully using for my first 4 JS8Call contacts. After using it at new ham's house this morning to show him how to adjust for a resonant antenna length (using the QMX's SWR sweep function), it now puts out 0.2 watts...and ONLY 0.2 watts...on all bands. Everything else is in the green on the diagnostics. This is my first kit rodeo and I assembled it 7 months ago. That's my first though (Factory reset did not change the issue). |
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Re: Low Band QMX Spectrum analyzer measurments
Thanks Ron,
I reckoned that if the manufacturer wrote the maximum limit on the front of the analyser that was what it would cope with. I'm running about half that power. I've got a home made attenuator attached to my home made 8W dummy load which is about 38.7 dB attenuation, I'll give that a go. Well you may have a point, using my home made attenuator puts the second harmonic at about -52 dB.That's relative to the primary that's about -2.5dBm My home made dummy load consists of 4x 2W 50R thick film SMD resistors, then a 2k2 through hole resistor with the output across 2x100R SMD resistors.? My NanoVNA suggests that it's quite linear. I wouldn't trust it for absolute power measurements but maybe it's better for relative power. dBc? Ah, relative to carrier. Must look for more attenuators at the next radio boot sale... Thanks, Chris, G5CTH |
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Re: QMX Feature Request - field “tune” mode
Chris G5CTH, The op said he wanted to protect the rig while adjusting his loading coil. If the connection to the antenna goes open while adjusting, what will the QMX finals see? Personally I wouldn’t chance it.? |
Timothy Fidler
Donald S Brant Jr